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Types and Uses of drill bit How should it be maintained?

Twist drill is a tool used widely in hole processing. Usually the diameter ranges from 0.25 to 80 mm. It is mainly composed of the working part of the bit and the shank. The working part has two spiral-shaped grooves, shaped like a twist, hence the name. In order to reduce the friction between the guide part and the hole wall during drilling, the twist drill gradually decreases its diameter from the drilling tip to the shank, showing an inverted cone shape. The spiral Angle of twist drill mainly affects the size of the front edge Angle, the strength of the blade and the chip removal performance, which is usually 25° ~ 32°. Spiral grooves can be processed by milling, grinding, hot rolling or hot extrusion. The front end of the bit is grinded to form the cutting part. Standard twist drill cutting part of the top Angle is 118, the cross edge Angle is 40° ~ 60°, the back Angle is 8° ~ 20°. Due to structural reasons, the front Angle is large at the outer edge and gradually decreases to the middle. The front Angle at the cross edge is negative (up to about -55°), which plays the role of extrusion during drilling.

What factors affect bit failure and the related causes of bit failure

Drill bit often fails, but it is difficult to find the cause of failure. Then, the following Xiaobian analysis of what factors affect drill bit failure. 1. Lithology The lithology and hardness of the strata are different, and the rock crushing mechanism is different, resulting in different forms of drill bit failure. The rock physical and mechanical properties of the common formation lithology in Chinese oilfield drilling have been determined. According to the formation lithology collected on site and drilling records per meter of lithology, the hardness, plasticity, brittleness, abrasiveness and drillability of the formation rocks are analyzed, and the failure forms of the bit are compared to confirm whether the selection and use of the bit is reasonable.